No. Iodine is a nonmetal, classified as a halogen on the periodic table.

How many protons does iodine have?

Iodine has 53 protons. Its atomic number is 53, which is also the number of electrons in a neutral atom of iodine.

What group and period is iodine in?

Iodine is in group 17 and period 5 of the periodic table, in the p-block.

What is the atomic mass of iodine?

The atomic mass of iodine is 126.9 u (unified atomic mass units).

Element 53

Iodine (I)

Halogen · Period 5 · Group 17 · p-block

Iodine (I) is element 53 of the periodic table, a halogen in period 5, group 17 (p-block) with an atomic mass of 126.9 and is a solid at standard conditions.

At a glance

Atomic number: 53
Symbol: I
Atomic mass: 126.9 u
Category: Halogens
Period: 5
Group: 17
Block: p-block
Phase at STP: solid

Electron structure

Electron configuration: 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p5
Shorthand configuration: [Kr] 4d10 5s2 5p5
Electrons per shell: 2, 8, 18, 18, 7
Oxidation states: -1, +1, +3, +4, +5, +6, +7

Physical properties

Melting point: 386.85 K (113.7 °C)
Boiling point: 457.4 K (184.25 °C)
Density: 4.93 g/cm³
Phase: solid

Atomic properties

Electronegativity (Pauling): 2.66
Atomic radius: 115 pm
Covalent radius: 139 pm
Van der Waals radius: 198 pm
First ionization energy: 1008 kJ/mol
Electron affinity: 295 kJ/mol

Notable isotopes

Notable isotopes of Iodine: mass number, atomic mass, natural abundance, and stability.
Isotope	Mass	Abundance	Stability
I-127	126.90447	100%	Stable

Common uses

Medicine
Photography
Disinfectants
Table salt

Discovery

Year: 1811
Discovered by: Bernard Courtois
Country: France

Frequently asked questions

Is iodine a metal?: No. Iodine is a nonmetal, classified as a halogen on the periodic table.
How many protons does iodine have?: Iodine has 53 protons. Its atomic number is 53, which is also the number of electrons in a neutral atom of iodine.
What group and period is iodine in?: Iodine is in group 17 and period 5 of the periodic table, in the p-block.
What is the atomic mass of iodine?: The atomic mass of iodine is 126.9 u (unified atomic mass units).

Keep exploring

Iodine's row is on the printable element property sheet, and its tile is on the periodic table wall chart - the same numbers as above, laid out for A4 or A3 paper.